Specific minerals are known to stimulate growth in agriculture. Fertilizers and other additives can include minerals such as calcium silicate, magnesium silicate, potassium silicate, and sodium silicate. Similarly, compounds such as gypsum (CaSO4H2O) can be used in agriculture (for example, as a soil stabilizer). Fertilizers and the other additives can deliver these minerals, these compounds, or combinations of these minerals and these compounds. The method of delivering the minerals or compounds, the crystal structure of the minerals or compounds, and the combination of the minerals or compounds impacts the efficacy of the fertilizers and other additives.
The minerals or compounds in the fertilizers or other additives can be natural (for example, mined) or synthetic (for example, a by-product of an industrial processes). Utilizing by-products can be environmentally beneficial by reducing waste and economically beneficial by creating economic value to existing waste. As described in U.S. Pat. No. 5,362,471, which is incorporated by reference in its entirety, synthetic gypsum is generally obtained as a by-product in the manufacture of phosphate containing fertilizers and as a by-product in the desulfurization of flue gas. According to U.S. Pat. No. 5,362,471, the synthetic gypsum has not experienced widespread commercial success because it has a different crystal size and shape than natural gypsum.
Another process of obtaining synthetic gypsum is described in U.S. Pat. No. 5,510,094, which is incorporated by reference in its entirety. The process described in U.S. Pat. No. 5,510,094 relates to treating the synthetic gypsum with ammonia and shows that a synthetic gypsum by-product from coal combustion can be used for agriculture upon being scrubbed with a slurry containing ammonia. The process does not include the combination of minerals that promote growth. Treating synthetic gypsum with anhydrous ammonia or a slurry containing ammonia can create an inhalation hazard with potential release of ammonia gas.
U.S. Pat. No. 6,939,387, which is incorporated by reference in its entirety, discloses a soil enhancer for use in the agriculture industry that does include certain minerals promoting growth. The patent disparages a product containing MgSiO3 as being unable to provide sufficient silicon to plants for a sustained period of time without frequent applications. The patent also disparages a product having at least 15% of a resulting pellet coming from a calcium source such as gypsum from cement operations as not permitting enough silica to be applied without applying large amounts of pellets. The patent describes a composition including a calcium silicate slag (specifically, a by-product of mining operations), magnesium sulfite particles, and water in a ratio of about 20:4:1 for a non-granulated compound and about 2:7:4 for a granulated compound. The combination suffers from the drawbacks that it does not have the soil stabilizing effects of gypsum, does not utilize by-products from processes other than mining, does not include the benefits of magnesium silicate, and calcium silicate. This combination is only able to provide enough soluble silicon under acidic soil conditions.
What is needed is an agricultural product and a method of forming an agricultural product that provides a sulfate source and calcium silicate that does not suffer from the drawbacks of the prior art.